Various projectile obturators have been designed in the past for assisting in various ways the launch of a projectile from a barrel, tube, and the like. For example, U.S. Pat. No. 4,242,961 discloses an obturator. The obturator base portion is generally made up of an elastomeric and nonmetallic material and of endless belt-like configuration for mounting in a groove as provided on the surface exterior of a projectile at its propellant end. By reason of the belt-like portion being mounted in the projectile groove, the obturator rotates relative to the projectile during launch thereby minimizing barrel rifling effects and rotation of the projectile about its axis. The outer peripheral portion of the base portion is provided with a series of annular and relatively spaced lips of chevron-like configuration in radial section for wipingly engaging the barrel interior surface so as to seal the propellant gases in the barrel thereby maximizing the performance of the projectile as it is launched from the barrel and moves along its intended trajectory to a designated target. The obturator may be of reinforced construction in providing annular extending fibers within the grooves between adjacent lips of the series thereof. U.S. Pat. No. 4,532,868 discloses a high performance projectile for use in a rapid, repetitive fire weapon and the like. The projectile is provided with an exterior band mounted in an annular groove of the projectile. One of the purposes of the band is to facilitate sliding action of the projectile in the weapon barrel. The band species of FIGS. 1-5 is considered pertinent and is of composite construction. The band is comprised of a base of ferrous, nonferrous material or an alloy thereof. The base is affixed to the projectile. The core of the band is made from tin bronze powder and polytetrafluoroethylene such that the polytetrafluoroethylene is scattered throughout the matrix of the nonferrous material in the form of ball-shaped elements. The exterior surface of the composite core is covered by a sheath or skin of polytetrafluoroethylene material. U.S. Pat. No. 4,552,071 concerns another obturator of two-piece construction. The obturator is made up of a base ring portion of flexible Nylon material for mounting in an annular groove on the exterior surface of a projectile between its ends. The bottom of the groove throughout its periphery is inclined such that the ring is in a lowered, retracted position when the projectile is loaded into a gun barrel. The outer surface of the ring is provided with a groove for receiving a narrow band of relatively hard Nylon material. The diameter of the outer surface of the band is such that it slidably engages and engraves itself upon the lands and grooves of the barrel as the projectile is inserted into the barrel with the obturator in a retracted position. The forward end of the ring is provided with a pair of relatively spaced annular lips. When the projectile is fired for launching from the barrel, the ring is advanced up the ramp to its extended position so that the lips extend radially outward so as to sealingly and wipingly engage the lands and grooves of the barrel interior. Since the ring is slippingly coupled to the ramp, spin rotation of the projectile is minimized as it is fired and launched from the barrel. However, none of the aforediscussed references, whether taken alone or in any combination, remotely suggest an improved multipurpose and preferably frangible projectile obturator of composite construction having, among other things, the purpose of maintaining a projectile in its initially oriented position when it is inserted in the barrel for cleaning (removing) propellant residue buildup, especially from the lands of a barrel interior, as the result of previous firing of another projectile. The obturator also provides a positive pressure seal between the obturator and the barrel when the projectile is fired, and then it fully separates itself, and drops away from the projectile after it is launched.